Nitrogen-removal-from-wastewater-using-membrane-aerated

NitrogenremovalfromwastewaterusingmembraneaeratedmicrobialfuelcelltechniquesChang-PingYua,b,ZhihuaLianga,AtreyeeDasa,ZhiqiangHua,*aDepartmentofCivilandEnvironmentalEngineering,UniversityofMissouri,E2509LafferreHall,Columbia,MO65211,USAbKeyLaboratoryofUrbanEnvironmentandHealth,InstituteofUrbanEnvironment,ChineseAcademyofSciences,Xiamen,361021,ChinaarticleinfoArticlehistory:Received26August2010Receivedinrevisedform22October2010Accepted4November2010Availableonline20November2010Keywords:WastewatertreatmentNutrientremovalMembraneaeratedsystemMicrobialfuelcellabstractNitrogenremovalmainlyreliesonsequentialnitrificationanddenitrificationinwaste-watertreatment.Microbialfuelcells(MFCs)areinnovativewastewatertreatmenttech-niquesforpollutioncontrolandenergygeneration.Inthisstudy,bench-scalewastewatertreatmentsystemsusingmembrane-aeratedMFC(MAMFC)anddiffuser-aeratedMFC(DAMFC)techniqueswereconstructedforsimultaneousremovalofcarbonaceousandnitrogenouspollutantsandelectricityproductionfromwastewater.During210daysofcontinuousflowoperation,whenthedissolvedoxygen(DO)inthecathodiccompartmentwaskeptat2mg/L,bothreactorsdemonstratedhighCODremoval(>99%)andhighammoniaremoval(>99%)butlownitrogenremoval(<20%).WhenalowerDO(0.5mg/L)wasmaintainedafterday121,boththeMFC-basedreactorsstillhadexcellentCODremoval(>97%).However,thenitrogenremovalofMAMFC(52%)was2-foldhigherthanthatofDAMFC(24%),indicatinganenhancedperformanceofdenitrificationafterDOreductioninthecathodiccompartmentoftheMAMFC.Meanwhile,terminalrestrictionfragmentlengthpolymorphism(T-RFLP)analysisofammonia-oxidizingbacteria(AOB)populationintheMAMFCindicatedthediversityofAOBwithequallyimportantNitrosospiraandNitrosomonasspeciespresentinthecathodicbiofilmafterDOreduction.TheaveragevoltageoutputintheMAMFCwassignificantlyhigherthanthatinDAMFCunderbothDOconditions.TheresultssuggestthatMAMFCsystemshavethepotentialforwastewatertreatmentwithimprovednitrogenremovalandelectricityproduction.ª2010ElsevierLtd.Allrightsreserved.1.IntroductionDecentral